As hardware for reproducing and storing high resolution video content or high quality video content is being developed and supplied, a need for a video coder/decoder (“codec”) for effectively encoding or decoding the high resolution video content or high quality video content is increasing. In a conventional video codec, video is encoded according to a limited encoding method, based on a macroblock having a predetermined size. In addition, the conventional video codec uses loop filtering to improve the quality of reproduced image data.